The present disclosure relates generally to nanorod light emitting devices.
Some modern light emitting devices produce light by using a combination of electrons and holes to inject electrical charge into a p-n junction structure corresponding to an active layer of a semiconductor. When electrons and holes are combined in an active layer of a semiconductor light emitting device, energy corresponding to an energy bandgap of the active layer may be emitted in the form of light, a phenomenon known as electroluminescence. Accordingly, the wavelength of light emitted from the semiconductor light emitting device may vary according to the size of the energy bandgap of the active layer. Examples of such semiconductor based light emitting devices include, but are not limited to, light emitting diodes (LEDs) and laser diodes (LDs). In particular, LEDs are generally regarded as being low-cost devices that are relatively efficient and environmentally friendly sources of light. This is particularly due to their ability to produce a relatively high level of brightness with relatively low power consumption. Consequently, LEDs are commonly used today as the preferred light source for a variety of general consumer products and electronic devices including, for example, displays, optical communications, motor vehicles, and other general devices that require a light source.
Recent developments in LED technology include the introduction of blue LEDs and ultraviolet LEDs using nitrides (or nitrogen based compounds). These new types of LEDs are known to have superior physical and chemical characteristics relative to conventional LEDs. Also, since a blue LED or ultraviolet LED may be combined with fluorescent material to produce either white light or other monochromatic light, these new LEDs have extended the range of applications for semiconductor light emitting devices in general. However, the nitride-based compound semiconductor crystals used to produce blue and ultraviolet LEDs are known to suffer from multiple defects. Defects in semiconductor crystals are generally caused by a mismatch in lattice constants or a difference in thermal expansion coefficients between a substrate and a compound semiconductor. Regardless of the cause of the defect, applying electrical charge by combining electrons and holes in crystals having defects may result in heat energy to be emitted by the LED instead of light energy, which in turn may reduce the luminous efficiency of the LED.